package Test;

import java.util.Scanner;

public class Main {

    class Solution {
        public void merge(int[] nums1, int m, int[] nums2, int n) {
            int i=m-1;
            int j=n-1;
            int k=m+n-1;
            while(i>=0&&j>=0){
                if(nums1[i]>nums2[j]){
                    nums1[k]=nums1[i];
                    i--;
                    k--;
                }else{
                    nums1[k]=nums2[j];
                    j--;
                    k--;
                }
            }
            while(j>=0){
                nums1[k]=nums2[j];
                j--;
                k--;
            }


        }
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        while (in.hasNextLine()){
            String str=in.nextLine();
            String string=func(str);
            System.out.println(string);
        }
    }
    private static String func(String str){
        boolean[] flg=new boolean[127];
        StringBuilder stringBuilder=new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char ch=str.charAt(i);
            if(flg[ch]==false){
                stringBuilder.append(ch);
                flg[ch]=true;
            }
        }
        return stringBuilder.toString();
    }
}
